Various orthopedic and other surgical techniques require the use of a suture anchor that engages bone. Common suture anchors are metal screws that have an eyelet at one end. The metal screws are driven into the bone. Suture is passed through the eyelet and is used to bring tissue into contact with the bone for healing. Metal suture anchors pose a number of associated risks, such as, but not limited to, bone fracture, anchor breakage and fragmentation, and anchor dislodgement.
Nonmetallic anchors are known, and typically take the form of soft material that is introduced into a hole that has been drilled into a bone. The anchor is then partially retracted from the hole, and as the result of friction against the side of the hole, bunches up to form a compact anchor as it is retracted, thereby holding to the hole and preventing a complete retraction. Unfortunately, sometimes there is insufficient friction to cause this to happen, and the anchor slips out of the hole, to no effect. Then, the process of attempting to set the anchor must be repeated, driving up time in surgery and possibly necessitating the use of an additional suture anchor.